Annuloplasty device for tricuspid valve repair

ABSTRACT

Annuloplasty device for implantation adjacent an annulus of a tricuspid valve, the annulus comprising anterior, posterior and septal aspects adjacent anterior, posterior and septal leaflets, respectively, of the tricuspid valve, the device comprising: a ring body comprising: an anterior portion, a posterior portion and a septal portion shaped to conform to, and for implantation adjacent, the anterior, posterior and septal aspects of the annulus, respectively; and first and second end portions that are more flexible than a remainder of the ring body to provide a gradual transition from the remainder of the ring body to tissue of the tricuspid valve annulus; wherein the ring body is curvilinear, with substantially no flat portions, and forming a shape. Related devices, kits and sizer devices.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation in part of U.S. Ser. No.12/011,482, filed Jan. 25, 2008, now U.S. Pat. No. 8,535,374 which isthe nonprovisional application claiming priority to ProvisionalApplication Ser. No. 60/897,696, filed Jan. 26, 2007, the entirecontents of each of which are fully incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to devices and methods forrepair of heart valves, and more particularly to an annuloplasty devicehaving two-dimensional (2D) and/or three-dimensional (3D) shape thateither mimics a healthy, native tricuspid valve annulus in shape orotherwise restores the annular shape of an incompetent tricuspid valveannulus to a shape more closely representing the 3D shape of a healthy,native tricuspid valve.

BACKGROUND OF THE INVENTION

Heart valve disease is a widespread condition in which one or more ofthe valves of the heart fails to function properly. Various surgicaltechniques may be used to replace or repair a diseased or damaged valve.In just one way, in a valve replacement surgery, damaged leaflets of thevalve are excised and the annulus is sculpted to receive a replacementvalve. Another less drastic method for treating defective valves isrepair or reconstruction by annuloplasty, in which the effective size ofthe valve annulus is contracted and reinforced, by attaching aprosthetic annuloplasty repair segment or ring to an interior wall ofthe heart around the valve annulus. The annuloplasty ring is designed tosupport the functional changes that occur during the cardiac cycle;maintaining coaptation and valve integrity.

One of the two atrio-ventricular valves in the heart is the tricuspidvalve. The tricuspid valve regulates blood flow between the right atriumand the right ventricle. Anatomically speaking, the tricuspid valve 10,as seen in FIG. 1, includes an annulus 12 that is the portion of thewall of the heart where three valve leaflets 14, 16, 18 (septal,anterior, and posterior, respectively) insert into the heart walltissue. The leaflets 14, 16, 18 extend inward into the valve or floworifice defined by the annulus 12. There are three commissures betweenthe three leaflets, which include an anteroseptal commissure 20, aposteroseptal commissure 22 and an anteroposterior commissure 24.Chordae tendinae 26 connect the leaflets to papillary muscles located inthe right ventricle to control the movement of the leaflets. Thetricuspid annulus 12 is an ovoid-shaped structure ring at the base ofthe valve. The annulus 12 has contractile function and can change shapethroughout a cardiac cycle. The portions of the tricuspid valve annulus12 that are attached to the septal 14, anterior 16 and posterior 18leaflets are called the septal 34, anterior 36 and posterior 38 aspects,respectively. The anterior and posterior leaflets are also known,respectively, as the anterosuperior and inferior leaflets. Similarly,the aspects of the annulus may be referred to using these alternativeterms.

With particular regard to the tricuspid valve, the primary dysfunctionis dilation of the anterior and posterior aspects of the valve annulus.Annulus dilation can lead to incomplete leaflet coaptation, causing acondition known as tricuspid regurgitation. Studies have shown that theposterior aspect can be dilated as much as 80% of its original length,whereas the anterior aspect can be dilated by as much as 40% (Carpentieret al. (1974), Surgical management of acquired tricuspid valve disease,Journal of the Thoracic Cardiovascular Surgeon, 67(1): 53-65). Theseptal aspect of the annulus lies along the atrioventricular septum ofthe heart and does not dilate as much as the other aspects (typically10% or less of its original length).

Consequently, when a tricuspid valve is repaired surgically, the goal isto reduce the size of and reinforce one or both of the anterior andposterior aspects of the valve annulus. Early methods used to reduce thesize of the anterior and/or posterior aspects were suture-based. Onemethod called “bicuspidization” used sutures to effectively eliminatethe posterior leaflet, and is described in Sharony et al. (2003), Repairof Tricuspid Regurgitation: The Posterior Annuloplasty Technique,Operative Techniques in Thoracic and Cardiovascular Surgery, November;8(4): 177-183. Another method called “sliding plasty” involvesseparation of the leaflets from the annulus, plication/shortening of theannulus, and reattachments of the leaflets, and is described in Minaleet al. (1987), New Developments for Reconstruction of the TricuspidValve, J. Thorac. Cardiovasc. Surg., October; 94(4): 626-31. Yet anothermethod used, called the “modified DeVega tricuspid annuloplasty,”involves placing a suture or series of sutures around the annulus andpulling the sutures tight to reduce the perimeter of the annulus, asdescribed in Antunes et al. (2003), DeVega Annuloplasty of the TricuspidValve, Operative Techniques in Thoracic and Cardiovascular Surgery,November; 8(4): 169-176.

One current method used to reduce the tricuspid valve annulus isremodeling annuloplasty. Remodeling annuloplasty involves implanting aprosthetic ring or band in a supra annular position. The purpose of thering or band is to restrict and/or support an annulus to correct and/orprevent valvular insufficiency. Remodeling annuloplasty is an importantpart of surgical valve repair. Three objectives of surgical valve repairinclude: 1) restore large surface of leaflet coaptation; 2) preserveleaflet mobility; and 3) stabilize the annulus and avoid furtherdilatation. In remodeling annuloplasty, both annuloplasty rings andannuloplasty bands are used for repair of valves. In general terms,annuloplasty rings completely encompass a valve annulus, whileannuloplasty bands are designed to primarily encompass only a portion ofthe valve annulus. Examples of annuloplasty bands are shown in U.S. Pat.Nos. 5,824,066, and 6,786,924, and PCT International Patent PublicationNo. WO00/74603, the teachings of which are incorporated herein byreference.

Annuloplasty surgery associated with the tricuspid valve is generallyintended to restore normal leaflet coaptation by reversing annulusdilation through plication. A way to restore leaflet coaptation is torestore the annulus to its normal or native shape during ventricularcontraction or systole. However, the shape of the tricuspid annulusduring portions of the cardiac cycle has not been well defined. Recentpublications provide evidence that the tricuspid valve annulus has anonplanar or 3D structure, which is described as “saddle-shaped,” andundergoes complex geometric changes during the cardiac cycle. (See,Fukuda et al. (2006), Three Dimensional Geometry of the TricuspidAnnulus in Healthy Subjects and in Patients with Functional TricuspidRegurgitation: A Real-Time, 3-Dimensional Echocardiographic Study,Circulation, 114: 492-498; Ton-Nu et al. (2006), Geometric Determinantsof Functional Tricuspid Regurgitation: Insights From 3-DimensionalEchocardiography, Circulation, 114: 143-149; Hiro et al. (2004),Sonometric Study of the Normal Tricuspid Valve Annulus in Sheep, TheJournal of Heart Valve Disease, 13(1): 452-460).

In close proximity to the tricuspid valve is the atrioventricular (AV)node 28 (FIG. 1). The AV node is a section of nodal tissue that delayscardiac impulses from the sinoatrial node to allow the atria to contractand empty their contents and also relays cardiac impulses to theatrioventricular bundle. In order to maintain AV node function, duringannuloplasty surgery, a surgeon generally attempts to avoid suturing inor near the AV node. Annuloplasty bands, or C-rings, are, therefore,good choices for use in repair of the tricuspid valve. The annuloplastybands include a break or opening that may be generally positioned in thearea including the AV node in order to avoid the need for suturing inthat area. However, since the AV node is not visible to the surgeon,there is the possibility that while securing the endpoints of theannuloplasty band, sutures may be placed in tissue including the AVnode.

The AV node is situated in the lower atrial septum at the apex of atriangle known as the Triangle of Koch (TOK), which is an area of hearttissue framed or bounded by certain anatomical landmarks in the heart.Two sides of the TOK are formed by the tendon of Todaro and the septalaspect of the tricuspid annulus. The base is marked at one end by thecoronary sinus orifice and the other end by the septal annulus. Theregion known as the TOK has been the focus of research relating to thecure of supraventricular arrhythmias that arise near the AV node.Additionally, surgical and catheter ablation techniques have made use ofthe TOK as an anatomic landmark for ablation.

Despite multiple annuloplasty methods and devices currently on themarket, there is a continued desire to improve such methods and devices.Particularly, there is a desire to have devices and methods that betteraccommodate the anatomy of the heart and the shape of the heartthroughout the cardiac cycle, and thereby improve results associatedwith valve repair surgery.

SUMMARY OF THE INVENTION

Annuloplasty devices for the tricuspid valve in the heart and relatedmethods were described in Applicants' co-pending United States patentapplication, having Ser. No. 12/011,482, and filed Jan. 25, 2008, theentirety of which is incorporated herein by reference. One advantage ofthe annuloplasty devices is that the healthy, native shape of thetricuspid valve may be, which thereby may improve function of the heartvalve into which the annuloplasty device is implanted. This close matchof normal anatomical shape could also increase durability of the repairby reducing stress on the leaflets. Another advantage is that theannuloplasty device can reduce stress on other parts of the heart, suchas the aortic valve for example, and thereby may improve the function ofthe heart into which it is implanted. An additional advantage is thatthe annuloplasty device can allow for a greater degree of plication ofcertain regions of the annulus to improve the function of the tricuspidvalve. In particular, the annuloplasty device may reduce the size of theposterior aspect of the annulus, which may thereby improve the functionof the tricuspid valve. Yet another advantage is that desired placementof the endpoints of the annuloplasty device can be determined in orderto avoid the AV node, such that electrical conductivity through theheart is not affected by the device or sutures used to secure the devicein place.

A further advantage of some of the embodiments of the present inventionis that when free ends of the annuloplasty device are either flexible orotherwise configured to curve away from the annulus, when the device isimplanted, force is distributed away from the endpoints of the device.The annuloplasty devices including flexible ends beneficially allow fora gradual transition between a stiffening element portion of the deviceand the surrounding tissue of the heart. Also, an advantage of a systemincluding annuloplasty devices of the present invention is that asurgeon may be given more than one choice of an annuloplasty device fora given size of valve annulus. The choice may include, for example,devices having different amounts of compression of the valve, and morespecifically compression or reduction of the area of the posterioraspect of the valve annulus. Yet another advantage of a system of thepresent invention is that sizers may be included that accurately measurethe size of a tricuspid valve annulus, which will result in a propersize of annuloplasty device being chosen and implanted.

One aspect of the invention is an annuloplasty device for implantationadjacent an annulus of a tricuspid valve, the annulus comprisinganterior, posterior and septal aspects adjacent anterior, posterior andseptal leaflets, respectively, of the tricuspid valve, the devicecomprising: a ring body comprising: an anterior portion, a posteriorportion and a septal portion shaped to conform to, and for implantationadjacent, the anterior, posterior and septal aspects of the annulus,respectively; and first and second end portions that are more flexiblethan a remainder of the ring body to provide a gradual transition fromthe remainder of the ring body to tissue of the tricuspid valve annulus;wherein the ring body is curvilinear, with substantially no flatportions, and forming a shape. The ring body may be configured such thatwhen the device is implanted, the first end portion will be located neara junction of the septal and anterior aspects of the annulus and thesecond end portion will be located near the septal aspect of theannulus. The ring body may further comprise: a sheath; and, a stiffeningelement disposed within the sheath. First and second end portions of thering body may comprise a flexible material. The stiffening element maycomprise a diameter that is reduced towards first and second ends of thestiffening element such that the stiffening element is more flexibletowards the first and second ends. The anterior portion may comprise acurve extending in a superior direction, the posterior portion maycomprise a curve extending in the superior direction, and the anteriorportion curve may extend farther in the superior direction than theposterior portion curve. The ring body may mimic the shape of a nativetricuspid valve annulus. The curvilinear shape may include varying slopebetween four slope minima. The ring body may follow a path from firstend portion to second end portion that contains at least two maximum andtwo minimum positions along the path. Upon implantation, the endportions of the ring body may avoid the AV node of the heart, or theTriangle of Koch of the heart.

A second aspect of the invention is an annuloplasty device forimplantation adjacent an annulus of a tricuspid valve, the annuluscomprising anterior, posterior and septal aspects adjacent anterior,posterior and septal leaflets, respectively, of the tricuspid valve, thedevice comprising: a ring body comprising: an anterior portion, aposterior portion and a septal portion shaped to conform to, and forimplantation adjacent, the anterior, posterior and septal aspects of theannulus, respectively; and first and second end portions; wherein thering body is curvilinear, with substantially no flat portions, forming ashape, and the ends are configured such that when the device isimplanted, the first end will be located near a junction of the septaland anterior aspects of the annulus and the second end will be locatednear the septal aspect of the annulus, and the anterior portioncomprises a curve extending in a superior direction that includes a peakand the peak will be located within about 20 degrees from the junctionof the septal aspect and the anterior aspect of the annulus and locatedadjacent the anterior aspect of the annulus when implanted. The peak ofthe anterior portion may be located about 10 to about 20 degrees fromthe junction of the septal and the anterior aspects of the annulus andlocated adjacent the anterior aspect of the annulus when implanted. Thepeak of the anterior portion may be located adjacent the junction of theseptal aspect and the anterior aspect of the annulus when implanted. Theposterior portion may comprise a curve extending in the superiordirection, the anterior portion curve extending farther in the superiordirection than the posterior portion curve. The posterior portion maycomprise a curve extending in the superior direction, the anteriorportion curve extending farther in the superior direction than theposterior portion curve.

A third aspect of the invention is a kit comprising a plurality ofannuloplasty devices for implantation adjacent an annulus of a tricuspidvalve, the annulus comprising anterior, posterior and septal aspectsadjacent anterior, posterior and septal leaflets, respectively, of thetricuspid valve, the plurality of annuloplasty devices each comprisingan anterior portion, a posterior portion and a septal portion shaped toconform to, and for implantation adjacent, the anterior, posterior andseptal aspects of the annulus, respectively, wherein the plurality ofannuloplasty devices are of a given size that correlates to a size ofannulus and each comprise a different amount of reduction in theseptal-lateral direction to improve septal leaflet coaptation to theposterior and anterior leaflets. The amount of reduction in theseptal-lateral aspect may be greater than about 25% and up to about 35%.The plurality of annuloplasty devices may include devices of additionalsizes and different amounts of reduction in the septal-lateral aspect.

A fourth aspect of the invention is a sizer device for sizing atricuspid valve annulus, the annulus comprising anterior, posterior andseptal aspects adjacent anterior, posterior and septal leaflets,respectively, of the tricuspid valve, the sizer device comprising: asizing plate; wherein the sizing plate includes markings that correspondto a junction of the anterior and septal aspects and a junction of theposterior and septal aspects. The shape of the sizing device may mimicthe shape of a native tricuspid valve. The sizing plate may comprise ananterior portion, a posterior portion and a septal portion shaped toconform to, and for placement adjacent, the anterior, posterior andseptal aspects of the annulus, respectively, in order to size theannulus, and wherein the anterior portion of the sizing plate includes acurve extending in a superior direction that includes a peak and thepeak will be located near the junction of the septal aspect and theanterior aspect of the annulus when placed adjacent the annulus. Thesizing plate may comprise an anterior portion, a posterior portion and aseptal portion shaped to conform to, and for placement adjacent, theanterior, posterior and septal aspects of the annulus, respectively, inorder to size the annulus, and wherein the anterior portion of thesizing plate includes a curve extending in a superior direction thatincludes a peak and the peak will be located about 10 to about 20degrees from the junction of the septal and the anterior aspects whenthe sizing plate is placed adjacent the annulus.

It is also contemplated by the present invention that the features ofthe embodiments described above or elsewhere herein or in theapplications incorporated herein by reference may be combined.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to theappended Figures, wherein like structure is referred to by like numeralsthroughout the several views, and wherein:

FIG. 1 is a plan view of a tricuspid valve and surrounding anatomy;

FIG. 2 is a top view of an exemplary annuloplasty band;

FIG. 3 is an isometric view of the exemplary annuloplasty band of FIG.2;

FIG. 4 is a side view of the exemplary annuloplasty band of FIG. 2;

FIG. 5 is a view from anterior portion end of the exemplary annuloplastyband of FIG. 2;

FIG. 6 is a schematic view of a stiffening element of the device thathas been opened and laid out providing a 2D view of the circumferentialside view of the stiffening element, showing slope minima;

FIG. 7 is a schematic view of a stiffening element of the device thathas been opened and laid out providing a 2D view of the circumferentialside view of the stiffening element, showing maximum and minimumpositions and range between them;

FIG. 8 is a top view of a tricuspid valve annulus, indicating positionsof the commissures;

FIG. 9 is a top plan view of an exemplary stiffening element forming onestructural component of an exemplary annuloplasty band of the presentinvention;

FIG. 10 is a top plan view of an exemplary annuloplasty band shownoverlapping an annuloplasty band of the same size but that includes areduced posterior and anterior portion;

FIG. 11 is a schematic representation of the area of the heart near andincluding the tricuspid valve;

FIG. 12 is the schematic representation of FIG. 11 with linesdemonstrating how the cylindrical coordinate system was established withregard to the tricuspid annulus;

FIG. 13 is a top and partial-cut-away view of an exemplary annuloplastyband;

FIG. 14 is a top view of a sizer device located adjacent a tricuspidvalve annulus;

FIG. 15 is a cross-sectional view of an exemplary annuloplasty bandincluding the stiffening element, a coating layer, and a sheath;

FIG. 16 is a top view of another exemplary annuloplasty band;

FIG. 17 is an isometric view of the exemplary annuloplasty band of FIG.15;

FIG. 18 is a side view of the exemplary annuloplasty band of FIG. 15;

FIG. 19 is a view from anterior portion end of the exemplaryannuloplasty band of FIG. 15; and

FIG. 20 is a schematic view of another stiffening element of the devicethat has been opened and laid out providing a 2D view of thecircumferential side view of the stiffening element, showing slopeminima.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

An annuloplasty device in accordance with the present invention is anon-planar or 3D annuloplasty device. Studies have shown that afunctioning tricuspid valve annulus is non-planar, and thus the presentinvention is particularly suited for repair of the tricuspid valve.Preferably, the annuloplasty device of the present invention mimicseither one or both of the 2D and 3D shapes of a healthy, nativetricuspid valve annulus, and preferably mimics the shape of a healthy,native valve annulus while in a portion of the cardiac cycle. Mostpreferably, the annuloplasty device mimics the shape of the healthy,native tricuspid valve annulus while the heart is in systole. Thepresent invention also includes methods of determining the shape of suchan annuloplasty device.

The annuloplasty device of the present invention preferably terminatesin free ends that when implanted in a tricuspid valve annulus avoidconductive tissue, such as the AV node. An opening or gap in theannuloplasty device between free ends is preferably positioned adjacentthe AV node to avoid the need for suturing in that area of the heart.Such an opening or gap may also facilitate appropriate surgicalattachment of the device to the annulus when a catheter and/or pacinglead has been placed through the tricuspid valve prior to the surgicalprocedure. The present invention also includes methods of determiningthe preferred location of such free ends of the annuloplasty device.

The embodiments of the present invention as shown in the accompanyingfigures and described herein are particularly designed for or relate tothe tricuspid valve. However, the present invention is not limited forapplication to the tricuspid valve, and it is contemplated thatvariations of the embodiments may apply to other valves.

With reference to the accompanying figures, wherein like components arelabeled with like numerals throughout the several figures, and,initially, to FIGS. 2-6, one embodiment of the first aspect of thepresent invention is illustrated. FIG. 2 illustrates a top plan view ofan annuloplasty band 50. Annuloplasty band 50 is generally arcuate(C-shaped), from a top view, as shown in FIG. 2. Annuloplasty band 50includes a septal portion 50 a adapted to generally be implanted on theseptal aspect of a tricuspid valve, a posterior portion 50 b adapted togenerally be implanted on the posterior aspect of the tricuspid valve,and an anterior portion 50 c adapted to generally be implanted on theanterior aspect of the tricuspid valve. The boundaries of the septal,posterior and anterior portions 50 a, 50 b, 50 c of the band 50 are notdefinite, however, since the drawing may not be to scale and because theanatomy of individual patients may be different (e.g., the lengths ofthe aspects of different patients' valve annuli may be different).

As discussed earlier, the terms anterior and posterior, with regard tothe leaflets of the valve, are also referred to as anterosuperior andinferior, respectively. Both terms may be used interchangeably. However,the present application will use the terms anterior and posterior.

When implanted, a first free end 51 and a second free end 52 of theannuloplasty band 50 may preferably be sutured to the septal aspect ofthe annulus. An opening or gap 55 is preferably present between the twofree ends 51, 52. Such an opening or gap preferably may cooperate withthe region of the annulus between the anteroseptal and posteroseptalcommissures (i.e., the septal portion of the annulus). An opening or gaplength can range between 0 mm (with the free ends touching) and the fulldistance between the anteroseptal and posteroseptal commissures.Preferably, the first end 51 extends past the anteroseptal commissurealong the septal aspect of the annulus, when implanted, so that at leastone suture can be made beyond the anteroseptal commissure along theseptal aspect of the annulus for stability of the septal aspect.

FIGS. 3-6 illustrate an isometric view, a side view, a view from theanterior portion end and a view from the posterior portion end,respectively, of the annuloplasty band 50 of FIG. 2. FIGS. 3-6 show thatthe annuloplasty band 50 preferably has a 3D shape that has a slopedprofile in the directions superior and inferior to the tricuspid valveannulus. The term “superior” as used herein refers to above thetricuspid valve annulus. The term “superior direction” as used hereinrefers to the direction extending above the tricuspid valve annulus,meaning generally towards the head while the tricuspid valve annulus isin place and oriented in the body. The term “inferior” as used hereinrefers to below the tricuspid valve annulus. The term “inferiordirection” as used herein refers to the direction extending below thetricuspid valve annulus, meaning generally towards the feet while thetricuspid valve annulus is in place and oriented in the body. The 3Dshape shown is one exemplary shape/configuration, however, other 3Dshapes are also contemplated by the present invention, which may mimicthe native, healthy shape of the tricuspid valve annulus and/or that mayimprove function of the tricuspid valve.

First 53 and second 54 sides of the annuloplasty band 50 are indicatedin FIGS. 4-6. If the annuloplasty band 50 was implanted in a valveannulus, blood flow would generally flow through from first side 53 tosecond side 54. In other words, if implanted, the first side 53 of theannuloplasty band 50 is preferably adjacent the atrial side of the valveand the second side 54 is preferably adjacent the ventricular side ofthe valve. Blood flow should be from superior to inferior or in theinferior direction as defined above.

The embodiment shown in FIGS. 2-6 includes an opening or gap 55 of acertain size. Different embodiments of the annuloplasty device of thepresent invention may have different sized openings or gaps between twofree ends of the annuloplasty device. The purpose of a smaller openingmay be to provide additional support for anchoring the device to thevalve annulus. The benefit of having a larger opening, however, may bethat fewer sutures are necessary in the septal potion of annulus toattach the device, which reduces possible effects caused by sutureplacement in and around the AV node. Moreover, as the septal leaflet hasa lesser tendency to dilate, there is less of a need for the septalannuloplasty band portion to extend farther along the septal aspect ofthe annulus.

The preferred shape of the annuloplasty device of the present inventionis substantially similar to the shape of a healthy, native tricuspidvalve annulus. In general, the preferred shape is curvilinear andcontinuously varying or curving, and includes substantially no flatportions, from first free end to second free end. “Flat” meansnon-curved in any of three dimensions. The anterior, posterior andseptal portions of the device together form the shape of the ring body.The anterior and posterior portions preferably comprise curves or bowingextending in a superior direction. The anterior portion curve or bowextends farther in the superior direction than does the posteriorportion curve. The shape of the ring body preferably emulates or mimicsthe shape of a healthy, native tricuspid valve annulus. Most preferably,the shape is determined in systole. The band is preferably configuredsuch that the first and second free ends 51, 52, when sutured to theannulus, are located at or near the anteroseptal commissure and alongthe septal aspect of the annulus, respectively.

With reference to FIGS. 2-6, one example of the preferred curvilinearand continuously varying or curving shape of the device as describedabove is shown. The band 50 comprises a curvilinear shape with a curve56 (FIG. 4) in the anterior portion extending in the superior directionand a curve 58 (FIG. 4) in the posterior portion also extending in thesuperior direction. The anterior portion curve 56 extends farther in thesuperior direction than does the posterior portion curve 58. Preferably,the curve 56 in the anterior portion may be sutured at or near theaortic valve when the device is implanted in an annulus. The shape inFIGS. 2-6 is believed to emulate the shape of a healthy, nativetricuspid valve annulus. However, other possible shapes are alsocontemplated.

In the case of an annuloplasty device of the present invention thatincludes two free ends, their preferred location is as follows: thefirst free end being configured and sized for a select tricuspid valvesize to be located near and slightly beyond the junction of the anteriorand septal portions; and, the second free end being located along theseptal portion. The first and second free ends, when the device isimplanted in an annulus, will preferably correspond to a location nearthe anteroseptal commissure (junction of anterior and septal aspects)and along the septal portion, respectively. Another preferred locationfor the two free ends is that both free ends will be located in theseptal portion of the device and, when implanted, correspond to theseptal aspect of the annulus. Preferably the two free ends are to belocated to avoid suturing of the ends near the area of the heart thatincludes the AV node, which could negatively affect conductivityrelating to the AV node.

With reference to FIG. 2, the first free end 51 is generally shown at ornear the junction of the anterior portion 50 c and the septal portion 50a or near the anteroseptal commissure when implanted. The second freeend 52 is generally shown in the septal portion 50 a. The figure is not,however, to scale, and represents one location for the two free ends 51,52. Other locations for the free ends of an annuloplasty band inaccordance with the present invention are, however, also contemplated bythe present invention.

The annuloplasty device of the present invention may include various 3Dshapes. As described above, a preferred 3D shape is curvilinear andcontinuously curving around its perimeter with substantially no flatportions. The preferred shape includes a curve in the anterior portionthat extends in the superior direction and a curve in the posteriorportion that extends in the superior direction, with the anteriorportion curve extending farther in the superior direction than theposterior portion curve. The curve in the anterior portion is preferablyconfigured to be located near the aortic valve when the device isimplanted around a tricuspid valve annulus.

In another embodiment, however, the 3D shape of a device, for example,may be described as a curvilinear shape with a generally varying slopebetween four minima (e.g., slope minima). The 3D, curvilinear slope isdefined in the directions superior and inferior with respect to thetricuspid annulus. FIG. 6 schematically and generally illustrates thisconcept by showing a stiffening element of the present inventive devicethat has been opened and laid out, providing a 2D view of thecircumferential (or perimeter) side view. The “slope minima” and“minima” and “minimum slopes” referred to with regard to FIG. 6 areindicated by 110. The location of the minimum slopes 110 can be variedaround the perimeter of the ring corresponding to specific anatomicallocations in order to preferably mimic a natural anatomic shape, whichmay provide improved valve function and reduce leaflet stress. A periodin the curvilinear shape between the slope minima 110 can also beadjusted by increasing or decreasing the rate of slope change betweenthe four slope minima 110, which may allow for both variable amplitudeand spacing between slope minima 110. The spacing between neighboringslope minima 110 preferably is at least one eighth of the perimeter ofthe device and is preferably no greater than half the perimeter of thedevice, which may control the amplitude and slope between neighboringslope minima 110.

In another embodiment, the 3D shape of the device may be described as acurvilinear shape that follows a path around the perimeter of the ringthat contains at least two maximum and two minimum positions along thepath. FIG. 7 schematically illustrates this embodiment by showing a sideview of a stiffening element of the present inventive device that hasbeen opened and laid out providing a 2D view of the circumferential sideview of the stiffening element. The maximum positions 111 and minimumpositions 112 can occur at desired positions along the perimeter of thedevice and correspond to desired positions along the annulus in order topreferably mimic the natural anatomical shape of the annulus, which mayprovide improved valve function and reduce leaflet stress. A preferredrange 113 between any maximum 111 and minimum 112, as shown in FIG. 7,may be no less than 10% of the linear distance 114 between theanteroseptal 115 and posteroseptal 116 commissures, as shown with regardto an annulus 119 in FIG. 8.

In yet another embodiment, the 3D shape of the device may be describedas a curvilinear, and 3D or non-planar (“non-planar” defined in thedirections superior or inferior with respect to the tricuspid annulus)shape along a span of the device that mates with an annular region 118of an annulus 119, as that shown in FIG. 8 with the annular region 118extending between the anteroseptal 115 and anteroposterior commissures117. The non-planar shape may preferably span at least 30% of the arclength (i.e., length of the annulus along the perimeter of the annulus)between the anteroseptal 115 and anteroposterior 117 commissures, with aminimum height (extending in the directions superior or inferior withrespect to the tricuspid annulus) above or below the annulus 119 of atleast 5% of the linear distance 114 between the anteroseptal 115 andposteroseptal 116 commissures.

The annuloplasty device of the present invention comprises a ring bodythat comprises a sheath or covering and a stiffening element within thesheath or covering. The annuloplasty device body preferably furthercomprise an opening or gap between two free ends of the coveredstiffening element. Details of the components are provided below.

The stiffening element portion of the annuloplasty device of the presentinvention is preferably designed to be covered and implanted in atricuspid valve annulus. In general, the stiffening element imparts ashape to the annuloplasty device, and is adapted to remodel, preferably,the tricuspid valve annulus. The stiffening element may comprise ametal, ceramic, polymer or a composite, for examples. Some desirableproperties of suitable materials for use in the stiffening elementinclude, but are not limited to, biocompatibility, biostability, andcorrosion- and fatigue-resistance. In some embodiments, the stiffeningelement is made of a material that imparts rigidity to the stiffeningelement, which in turn imparts rigidity to the annuloplasty band. If thestiffening element comprises a metal wire, the wire can be formed of anymedically-acceptable, implantable, biocompatible metal, such ascobalt-nickel alloy (MP35N™), cobalt-chromium alloy (Elgiloy™, Haynes25™), titanium, stainless steel, shape memory materials such asnickel-titanium alloy (Nitinol™), or other similar inert biocompatiblemetal.

The stiffening element may generally have a circular cross-section.However, cross-sections of other shapes are also contemplated by thepresent invention (e.g., square, rectangular, elliptical, triangular, orthe like). Different cross-sectional shapes can be used to impartvarying degrees of bending or torsional stiffness depending on thebending/twisting plane with respect to the section modulus. Also, thecross-sectional shape may be varied around the perimeter of thestiffening element, which may vary the stiffness around the perimeter.

Preferably, the stiffening element may be covered or overmolded with abiocompatible, biostable, implantable medical grade elastomericprotective coating, such as an elastomeric thermoplastic polymer (e.g.,polyurethane) or a silicone (e.g., liquid silicone rubber) to provide aconsistent profile and to create desirable needle penetration propertiesfor the surgeon. Also, coating can impart radiopaque and echogenic invivo visualization, for example. Alternatively, the protective coatingmay be tubing within which the stiffening element is disposed, thetubing consisting of biocompatible, biostable, implantable medical gradeelastomeric material, such as elastomeric thermoplastic polymer (e.g.,polyurethane) or silicone. In yet other embodiments, the protectivecoating may be eliminated.

The stiffening element, with or without the protective coating, ispreferably covered with a sheath or covering. The covering or sheath maycomprise a knitted polymeric fabric (e.g., polyethylene terephthalate orDacron™), although woven, non-woven materials (e.g., spun-bond,melt-blown, staple fiber matrix, etc.), braided fabrics, or metallicbraids (e.g. titanium, Nitinol, and stainless steel wires) are alsocontemplated, as well as sheaths formed of harvested biological tissue(e.g., pericardial tissue). The covering or sheath may optionally beprovided with any of various biocompatible coatings. The preferredpurpose of the covering or sheath is to provide a site for attachment ofthe device to the annulus using invasive or minimally invasive surgicaltechniques as well as to allow for in-growth of the device with thenative valve tissue. A plurality of knotted sutures is typically used tosecure the annuloplasty device to the tricuspid annulus, although otherfasteners such as staples, fibrin glue, or the like may be used.

A preferred cross-sectional shape for a stiffening element is shown inFIG. 15, wherein a stiffening element 81 has a generally squarecross-section. An elastomeric coating 87 and a sheath 83 are alsoillustrated in cross-section, respectively, as overlaying the stiffeningelement 81. The coating 87 can be provided as overmolded or coated ontothe stiffening element 81, such as by any conventional overmolding orcoating technique. Or, the coating 87 can be provided as a tubing orhose of elastomeric material with an open central lumen of a size andshape to receive the stiffening element 81 (in the preferred case, as asquare lumen). An advantageous feature of the coating 87 that isillustrated in FIG. 15 is the provision of an enlarged portion 89 thatis provide on one side of the stiffening element 81. As shown, theenlarged portion is provided to a side surface that is along an outercircumference of the annuloplasty band or ring body to facilitate easiersuturing of the annuloplasty band to the tissue of a tricuspid valveannulus. A suturing needle 88 is shown as passing through the enlargedportion 89 of the coating 87 as part of a suturing step. The size andshape of this enlarged portion 89 can be varied for the purpose offacilitating any specific suturing technique, and it is contemplatedthat other surfaces of the stiffening element can be otherwise oradditionally provided with a similar or different enlarged portion forsimilar purposes, as may be needed to improve suturing to tissue atspecific annulus locations. In this regard, it is further contemplatedthat the coating 87 can vary along its length for this or similarpurposes.

The stiffening element may also be radiopaque, echogenic, MRI-compatibleand/or otherwise imaging enhanced so that it may readily be visualizedafter implantation using various existing techniques or any futuredeveloped techniques, including x-ray, MRI, echogram, etc. By“radiopaque,” it is meant that the material or element prevents thepassage of radiation. “Radiation” is meant to include electromagneticenergy, light, etc. By “echogenic,” it is meant that it reflects soundwaves. By “MRI-compatible” it is meant that the material or element isboth MRI safe and capable of being excited by MRI.

The annuloplasty device of the present invention may have any amount offlexibility. Preferably, the device has a sufficient elasticity thatallows the band to return to an original shape after physiologic forcesare applied and removed to the device and the device is in a free state.For example, the device may be rigid or semi-rigid. The rigidity of thedevice may be varied depending upon the material comprising the deviceand/or the construction of the device. For example, the rigidity of thedevice can also be controlled by controlling the material and shape/sizeof the cross section of the stiffening element.

In some embodiments of the present invention, in particular anyembodiments having a stiffening element comprising a semi-rigid materialand two free ends, the stiffening element may have eyelets (not shown)at one or both of its two free ends, which may be used to suture theends and anchor them to fibrous tissue of the annulus (e.g., theseptum). The eyelets may be formed by the stiffening element being bentback onto itself at one or both of the first and second free ends.Alternatively, the eyelets may be integrally molded with the rest of thestiffening element, or can be subsequently assembled to the stiffeningelement. As used herein, “eyelet” means an opening with a substantiallyclosed perimeter, but does not require a specific shape (e.g., an eyeletcan be round, square, rectangular, trapezoidal, hexagonal, tear-drop,oval, elliptical, or any other suitable shape), although shapes withlower stress concentrations are preferred. The eyelets are preferablyadapted to receive at least one suture to secure the annuloplasty deviceto a valve annulus or a heart valve, such as the tricuspid valve.

In some embodiments, one or both of the free ends of the ring body wouldinclude a more flexible or compliant segment or portion. Alternatively,end portions of the ring body may have reduced stiffness from theremainder. One purpose of the more flexible or less stiff segment wouldbe to allow for a more gradual compliance of the device with surroundingtissue at one or both of the ends of the ring body. The flexible or lessstiff segments allow for a gradual transition from the stiffeningelement of the device to the surrounding tissue. The more flexible orless stiff ends also allow force to be distributed away from theendpoints of the stiffening element.

The flexible segments may be formed by providing an amount of flexibleor complaint material to one of both of the free ends of the stiffeningelement, for example. Such flexible material can be attached to an endof the stiffening element or positioned there and otherwise restrainedin place. In the case of the provision of an elastomeric coating 87, asdescribed above, to the stiffening element 81, the elastomeric coatingcan be extended to provide the flexible material as extending beyond theend or ends of the stiffening element. FIG. 13 shows a tricuspid valveannuloplasty device 80 in a top, partial cut-away view. The band 80comprises the stiffening element 81 that is surrounded by sheath orcovering 82. The sheath 82 is partially cut away at end sections of thedevice 80 in the figure, allowing inside of the ends 83, 84 of thedevice to be seen. One or both of the ends of the stiffening element 81can have extension segments of a more flexible or complaint material,such as shown at both ends as elements 85 and 86, than the remainder ofthe stiffening element. These extension segments 85, 86, can be madeseparately from the stiffening element 81 and attached thereto. Ifseparately made, such segment can be connected with the free ends of thestiffening element, such as by an adhesive, welding, or the like, may bejust positioned there and held in place by constraint of the sheath 82,or may be provided as an extension of a coating that is applied to coverthe stiffening element 81. Alternatively, in an integrated design, aflexible extension could be provided as an extension of the stiffeningelement that is effectively decreased in diameter or changed in itscross-sectional shape toward the free ends 83, 84, of the device 80,which would make the extension or extensions of the stiffening element81 more compliant or more flexible in those areas. It is contemplatedthat variations of flexibility or the stiffness and/or shape can vary aswell along these more compliant segments 85 and/or 86. Thus, acontrolled force distribution for one or both ends of the stiffeningelement of the ring body can be designed into the ring body. Then, whenthe ring body is sutured to the tricuspid valve annulus, for example,the force at one or both ends as is generated to the annulus at the ringbody ends as a result of suturing can be controllably distributed to theadjacent tissue including the portion of the annulus that is within thegap that is provided between the ends of the ring body including the AVnode. Another advantage of such force distribution at the ring body endsis a to reduce the likelihood of late dehiscence near the ends of thering body within the annulus tissue as a result of suturing the ringbody to the annulus. That is, forces that might tend to split suturedtissue are spread out or distributed to adjacent tissue to reduce thelikelihood of such tissue dehiscence.

An exemplary material that may be used for the flexible or compliantextension segments 85, 86 is an elastomeric material, such as silicone.Other materials and combinations of materials are also contemplated bythe invention, however, and are not limited to those described herein.

In a preferred embodiment, the flexible or compliant extension segmentsare about 1-10 mm in length, preferably extending over at least the last3-5 mm of the device, however other lengths are also contemplated aseffective to provide a desired controlled force distribution at one orboth of the ends. Ends can have similar or different lengths of flexibleextension as determined for effective controlled force distribution, asdesired. The lengths of the segments function to provide a desiredamount of gradual transition between the stiffening element and the endsof the device. For effectiveness, it is preferred that any such flexibleextension have a length that is at least greater than thecross-sectional dimension or diameter of the stiffening element.

The flexible extention segments may be shaped in order to be useful fora given device and purpose. For example, the cross-section of theflexible extension segment may be circular, but other shapes are alsocontemplated, which shape changes can be utilized as part of acontrolled force distribution at one or more of the ring body ends.

When implanted, one end of the device may be placed at or near theantero-septal commissure in the valve annulus and the other end may beplaced at or near the septal aspect of the annulus (most preferably, ator near the middle of the septal aspect). With a device that includesone or both flexible extension segments, then the ends of the stiffeningelement may be located at the same position as described above, with theflexible extension segments extending further along the circumference ofthe valve annulus for controlled force distribution beyond the ends ofthe stiffening element. The provision of such a flexible extension is ofparticular benefit when provided at the end of the stiffening elementthat is to be positioned along the septal aspect of the annulus. It isalong the septal aspect of the tricuspid annulus that dehiscence is morelikely to occur after implantation of the ring body. The result of acontrolled force distribution at this end of the ring body along theseptal aspect is a reduction of the likelihood of such dehiscence.Alternatively, however, the ends of the flexible extension segments maybe located at or near the positions described above. The inventioncontemplates, however, that various combinations of end point locationsmay be used.

In some embodiments, construction of the annuloplasty device preferablyprovides a low profile attribute. More particularly, the cross-sectionaldiameter or width would preferably range from about 0.03 to about 0.20inches, with the stiffening element portion having a cross-sectionaldiameter or width ranging from about 0.005 to about 0.150 inches.However, other ranges of diameters and widths are also contemplated bythe present invention. A purpose of the low profile is to minimizedisturbance to blood flow and potential thrombus formation.

A stiffening element portion of another embodiment of the annuloplastydevice of the present invention is shown in FIG. 9. The stiffeningelement 76, seen in a top plan view, has an opening or gap 75 betweentwo free ends 71, 72 of the stiffening element, and an inward curvature77 in the anterior portion 70 c, which corresponds to an anterior aspectof an annulus, and near the first free end 71. The inward curvature 77curves inward toward the flow or valve orifice in the region that mayinterface with an anterior aspect of an annulus and that may be locatednear an aortic valve when a device including the stiffening element 76is implanted adjacent a tricuspid valve annulus. The inward curvature 77can allow the aortic valve to open more fully because the stiffeningelement 76 of the device does not enter or protrude into the area of theaortic valve and avoids the aortic valve. As a result of avoiding theaortic valve, the curvature 77 can minimize distortion of the aortaduring a cardiac cycle. This embodiment may be combined with the 3Dshapes of the device that are described above.

Another optional feature of the present invention allows forovercorrection of valve dilation along the posterior aspect of thetricuspid annulus by reducing the length of the posterior portion of aring relative to a measured valve size. FIG. 10 illustrates how thelength of the posterior annulus portion may be reduced to correct valvedilation. In FIG. 10, two annuloplasty bands 100 (demonstrating thisembodiment of the present invention) and 101 (an exemplary prior artband) are laid one on top of the other so that the anterior portions andthe free ends near the anterior portions are aligned. Theseptal-lateral, otherwise known as the septal-anterolateral, distance102 of the portion of the stiffening element 100 corresponding to theposterior aspect of an annulus is shorter than the length 103 of theportion of stiffening element 101 corresponding to the posterior aspect.The distance 104 between the free ends in both stiffening elements 100,101, however, for both bands is shown as substantially the same. As canbe seen in FIG. 10, the reduction in the length of the posterior portion102 from posterior length 103, while maintaining the distance betweenthe free ends 104, results in a reduced curvature along the posteriorregion of the stiffening element 100 from stiffening element 101. Sincethe size of an annuloplasty device may be dependent upon the distancebetween the free ends, the result is a stiffening element 100 ofgenerally the same size as stiffening element 101, but with a reducedcurvature along the posterior portion. The purpose of this embodiment ofthe present invention is to ensure sufficient leaflet coaptation withoutglobal downsizing of the valve annulus. This embodiment may be combinedwith the 3D shapes of the device that are described above.

According to preferred aspects of the present invention, an annuloplastyband 100 is designed to have at least about 25% reduction of theseptal-lateral dimension over the anatomical measurements of a typicaltricuspid valve annulus. Moreover, it is preferable to provide areduction of between 25% and about 33% for improved effectiveness incoaptation of the valve leaflets. That is to say, that if theillustrated band 101 were to have a curvature in the posterior regionthereof, in the plan view as shown in FIG. 10, that includes aseptal-lateral dimension indicated by 103 that is based upon a measuredseptal-lateral dimension of a tricuspid annulus a preferred band 100would have at least a 25% reduction of the septal lateral dimension soas to enhance coaptation between the leaflets. As illustrated, thereduction of curvature of the posterior region of the band 100 reducesthe septal-lateral dimension of the band 100 to the dimension 102 (ascompared with a measured anatomical septal-lateral dimension) and alsoreduces a dimension 105 between the end of the band to be implanted nearor at the anteroseptal commissure (junction of anterior and septalaspects) and the inside curvature of the posterior region of the band100. Based upon this combination of reductions in design of the band100, as compared to measured anatomical dimensions, coaptation of theseptal to the anterior leaflets is enhanced as is the coaptation of theposterior leaflet with both the septal and anterior leaflets. Coaptationbetween all of the tricuspid leaflets is effectively enhanced. Withinsufficiency of a tricuspid valve annulus, it is often the case thatthe right ventricle becomes enlarged and increased cinching of thetricuspid annulus, as the effect of a reduction of the septal-lateraldimension, effectively enhances coaptation of the leaflets and valveperformance efficiency.

The invention also contemplates a system or kit of annuloplasty devicesthat provides several different sizes of tricuspid valve annuloplastydevices. Any number of different sizes, but preferably at least sixsizes of devices will be included in the system or kit, with preferredsizes including at least 26 mm, 28 mm, 30 mm, 32 mm, 34 mm, and 36 mm.These sizes are based upon a measured anatomical size of certain commontricuspid valve annulus sizes. However, other sizes of devices are alsocontemplated by the invention.

The invention also contemplates a system or kit of annuloplasty devicesof either one size or multiple sizes in which the system or kit includesmore than one annuloplasty device of a given anatomical size that havedifferent septal-lateral dimensions or lengths of the posterior portionof the device (i.e., different amounts of compression of the posterioraspect of the annulus). Preferably, devices having reduced lengths ofthe posterior portion will be provided, although it is contemplated thata different dimensional aspect of a variety of bands all relating to acommon anatomical size can be combined in accordance with this aspect ofthe present invention. The purpose of the reduced length of theposterior portion, as discussed above, is to reduce curvature along theposterior region of the device, which may enhance leaflet coaptationwithout global downsizing of the valve annulus. The different lengths ofposterior portions may result in different levels of coaptation of theleaflets of the valve. In particular, as above, it is preferred that apreferred band in accordance with the present invention include at leasta 25% amount of reduction or compression. It is contemplated that such areduction can be increased to as much as about 33%. Devices havingdifferent percentages of compression, or different compression ratios(e.g., 5%-33%), however, may be provided and are contemplated.Therefore, the invention includes a kit of devices that may have onesize or multiple sizes, and for each size there are, for example, aplurality (e.g., 2 to 5) different devices available in that size to aphysician during surgery that include different levels of compression orreduction of the septal portion (effecting a reduction in the septalaspect of the annulus upon implantation).

The present invention also contemplates a system that includes holdersand sizers correlating in shape and size to the annuloplasty device ofthe present invention, which may differ in size and shape. Such holdersassist in implantation of a ring or band in a patient, and such sizersassist in choosing the correct size of device for a given valve or valveannulus of a patient.

Sizers are used to size the tricuspid valve annulus prior to a surgeonchoosing a particular device for annuloplasty surgery. Another aspect ofthe invention is a sizer that accurately measures the anatomicaldimensions of a tricuspid valve annulus. Inventive sizer devices inaccordance with the present invention measure the septal leaflet, orseptal aspect of the annulus, which allows the correct size ofannuloplasty device to be chosen to be implanted in the tricuspid valveannulus. A sizer device 90 is shown in FIG. 14 as it is used to size atricuspid valve annulus 12.

The sizer device 90 comprises a sizing plate portion 91 that is shapedto correspond to annuloplasty devices of the present invention. Thus,the sizing plate portion 91 may include two-dimensional (2-D) shapeand/or three-dimensional (3-D) shape corresponding to those describedannuloplasty devices. The sizing plate 91 preferably comprises amaterial that a surgeon can see through in order to see the leaflets ofthe heart valve (14, 16, and 18 in FIG. 14, with dashed lines indicatingwhere the leaflets coapt together) and ensure proper sizing.

The sizer device 90 also comprises an attachment hub 92 that isgenerally in or near the center of the sizing plate 91, and allows anelongate member (not shown) to attach to the sizer device 90 and be usedto deliver the sizer device 90 within close proximity of the tricuspidvalve annulus for sizing of the annulus. The attachment hub 92preferably allows the sizer device 90 to be removably attached to theelongate member.

The sizing plate 91 preferably includes markings, indentations orcut-out portions 93 and 94 that will correspond to a patient'scommissures. In particular, a cut-out 93 is illustrated that correspondsto the anteroseptal commissure and a cut-out 94 is illustrated thatcorresponds to the posteroseptal commissure. The cut-outs 93, 94,therefore, determine an effective dimension of the septal leaflet of thevalve.

The sizing plate 91 also preferably includes a gap 95 that correspondsto an opening or gap in an annuloplasty device between two free ends ofthe device, as described herein with regard to the inventiveannuloplasty devices. As shown, the gap portion 95 corresponds to a gapwhere a first end of a annuloplasty device extends further past theanteroseptal commissure and along the septal aspect while the second endis to be located also along the septal aspect in a more mid-pointthereof.

FIG. 4 shows an annuloplasty device of the present invention with asuperior-extending curve 56 in the anterior portion. The peak of thecurve may be alternatively be located at various locations along theanterior portion of the device. One embodiment even includes the peak ofcurve 56 being located at the anteroseptal commissure when the device isimplanted. Other embodiments locate the peak of curve 56 between about10 degrees to about 20 degrees clockwise from the anterospetalcommissure, for example. Two preferred embodiments include the peak ofthe anterior curve at 10 degrees and 20 degrees from the anteroseptalcommissure.

A marking of the anteroseptal commissure attachment point is preferablyincluded on the embodiment of the annuloplasty device of the invention.The marking may assist a surgeon in implanting the device, such that themarking is lined up with the anteroseptal commissure duringimplantation. A marking of the posteroseptal commissure attachment pointmay also be included on the device.

The devices and sizers of the invention include 2-D and/or 3-D shapesthat complement each other. Therefore, the sizers of the invention alsopreferably include a curve in an anterior portion that corresponds tothe curve 56 of the device 50. The sizer 90, with or without the curve,preferably is marked where the sizer is to be lined up with theanterospetal commissure upon implantation (as discussed above). The peakof the anterior curve of the sizer 90 may be located so as to line upwith the anteroseptal commissure upon implantation, or alternatively belocated between about 10 degrees to about 20 degrees clockwise from theanteroseptal commissure.

The present invention relates to methods of determining the shape andconfiguration of an annuloplasty device used to repair a tricuspidvalve. One method is for determining a shape of an annuloplasty devicefor tricuspid valve repair, the method comprising the steps of:determining specific anatomical features of a heart; determining theshape of the tricuspid valve annulus in the heart; and using theanatomical features of the heart and shape of the annulus to determinethe shape of the annuloplasty device. At least one of the determiningsteps may be performed using at least one imaging technique on at leastone heart. The at least one imaging technique may be selected from thegroup consisting of: radiographic means, echogenic means, computedtomography, magnetic resonance imaging, other currently existing imagingprocesses, or any future developed imaging techniques. The method mayfurther comprise the steps of: using the anatomical features of theheart to determine the Triangle of Koch; and locating free ends of thedevice such that the free ends will not contact the Triangle of Kochwhen the device is implanted.

FIGS. 16-20 illustrate certain aspects of another annuloplasty device500 for a tricuspid valve annulus in accordance with the presentinvention. As shown in FIG. 16, an open band includes a first end 502and a second end 504 providing a gap 506 between the ends. A firstmarking 508 is preferably provided to indicate the anteroseptalcommissure, a second marking 510 is preferably provided to indicate theanteroposterior commissure, and a third marking 512 is preferablyprovided to indicate the posteroseptal commissure. The distance betweenthe markings 508 and 512 (including the gap 506) preferably relatedirectly to a measured distance between the anteroseptal commissure andthe posteroseptal commissure, which distance is measured as the lengthof the septal aspect or leaflet of a tricuspid valve annulus. The lengthof the septal aspect of the annulus is considered to be a primaryindicator of the size of the annulus for the purpose of determining thecorrect sizing of an annuloplasty device in accordance with the presentinvention and as discussed above. The position of the anteroposteriorcommissure and the related marking 510 is of less consideration, but canalso be important. It may be the case that a properly fit annuloplastydevice would be based upon the length of the septal aspect of atricuspid annulus but with the marking 510 at a location to one side orthe other of the anteroposterior commissure location. In this regard, itis also contemplated that the marking 510 could instead comprise eithera series of similar or dissimilar markings or could comprise a shadedsection of the band, or the like, to indicate a preferred range of wherethe location of the anteroposterior commissure should be located with aproperly fitting annuloplasty device. Otherwise, FIG. 16 shows featuressimilar to that of FIG. 2, discussed above, with an anterior portionthat is designed to extend along the anterior aspect and then fartheralong the annulus past the anteroseptal commissure and a short distancealong the septal aspect. As such, the first end 502 of the annuloplastydevice 500 will be located along the septal aspect of a tricuspidannulus along with the second end 504, although separated from oneanother by the gap 506 to accommodate at least the AV node, as alsodiscussed above. Like the embodiment discussed above with respect toFIG. 2, the annuloplasty device is noted as being divided intocorresponding device portions including an anterior portion 514(although an end portion thereof is intended to be implanted along aportion of a septal aspect of a tricuspid annulus), a posterior portion516 and a septal portion 518.

In FIGS. 17, 18 and 19, an annuloplasty device 500 is shown from aright-side, front-side, and left-side views as having a curved nature ineach of the three dimensions from end 502 to end 504. That is to saythat the anterior portion 514, the posterior portion 516 and the septalportion 518 are each preferably curvilinear in each of the threedimensions. In this illustrated embodiment, a first curve 520 isprovided along the anterior portion starting from the first end 502 inthe superior direction (arrow A). This first curve 520 includes a peakthat is preferably designed so as to be located near the anteroseptalcommissure when implanted. Most preferably, the anteroseptal commissureis to be located at the marking 508 and the peak is slightly toward thefirst end 502 from the marking 508. The remainder of the anteriorportion 514 preferably comprises a generally shallow inferior curvaturethat begins to curve again in the superior direction in approach to theposterior portion 516 of the annuloplasty device 500. A second curve 522in the superior direction preferably lies primarily within the posteriorportion 516. A portion of the second curve 522 preferably includes apeak that lies between the anteroposterior marking 510 and theposteroseptal marking 512. From a side view of the second curve 522, themarking 512 as implanted is most preferably designed to be implantedlower or more inferior than the marking 510 as implanted. As such, theposterior portion 516, as preferably designed between the markings 510and 512, comprises a superior curve that is higher on one side (at themarking 510) than at the other side (at the marking 512), as theannuloplasty device is positioned at implant. Then, the septal portion518 of the annuloplasty device 500 as extending from the posteriorportion 516 generally comprises a gradual transition from the superiorcurvature of the second curve 522 to a slightly inferior curve thatleads to the device second end 504.

The nature of the preferred curvature of the annuloplasty device 500 ofFIGS. 16-19, with respect to the curves of the device in the superiorand inferior directions, is illustrated in FIG. 20, which shows thedevice as if opened and laid out flat in a similar manner as in FIGS. 6and 7. According to this preferred embodiment, the peak of the firstcurve 520 is designed to be higher, or more superior, than the peak ofthe second curve 522. It is, above, contemplated that the position ofeach peak of the curves 520 and 522 can vary along the length of thedevice and that the amplitudes of one or both likewise can vary. FIG. 20also illustrates a preferred composition of the device 500 as comprisinga stiffening element 524 that is coated by an elastomeric layer 526 anda sheath 528. The first end of the device includes an elastomericextension portion 530 and the second end includes an elastomericextension portion 532 that is of greater length than the first extensionportion 530, such as discussed above, and can be made as extensions ofthe elastomeric coating layer 526.

The Example below describes how the shape and configuration (includinglocation of the ends) of the device may be determined. Other methods arecontemplated by the present invention, however.

EXAMPLE

Six sets of human heart data were analyzed in order to assess the shapeof the tricuspid valve annulus. Datasets included one MRI dataset (MRI1)collected during systole and five CT datasets (CT1-CT5) collected duringan arbitrary portion of the cardiac cycle. The data collected werecomposed into Digital Imaging and Communication in Medicine (DICOM)(available from Laurel Bridge Software, Inc., located in Newark, Del.,U.S.A.) image files, which were then imported into Mimics® software(available from Materialise, located in Belgium). Utilizing the Mimics®software, left and right sides of the heart, in the images, weresegmented by differentiating image contrast between the blood volumewithin the heart chambers and the heart tissue. The image pixels fromthe image were grouped (i.e., color coded) based on defining levels ofimage contrast below which all pixels with contrast less than thedefined level were grouped (i.e., thresholding), with remaining pixelsabove the contrast level grouped separately. After thresholding, thetricuspid valve annulus was identified and the shape reconstructed, andother anatomical landmarks or features in the heart were identified.

FIG. 11 is a schematic representation of the area of the heart near andincluding the tricuspid valve 200 from a superior perspective withrespect to the annulus. The aortic valve 202 is schematicallyrepresented, as well as the membranous septum 204 of the heart, and thecoronary sinus 206. The anterior 208, posterior 210 and septal 212leaflets, and the anteroseptal 214, anteroposterior 216 andposteroseptal 218 commissures of the tricuspid valve 200 are alsoillustrated. Also, the right coronary cusp 220 and the non-coronary cusp222 of the aortic valve 202 are shown. Between the two cusps is theright coronary/non-coronary commissure 221.

Axes and other boundaries were constructed, as shown on FIG. 12, fromanatomical landmarks in the heart, which were used in the analysis ofthe six datasets. A major axis 230 and a minor axis 232 of the tricuspidvalve 200 were determined. Also, the Triangle of Koch (TOK) 224 wasdetermined. The TOK height 226 (or base of triangle) extends between thecoronary sinus orifice 206 and a point 236 normal to the coronary sinusorifice 102 along the septal aspect of the tricuspid annulus 234. TheTOK length 228 (one side of triangle) extends between the coronary sinusorifice 206 and the location 238 where the septum 204 and the tricuspidvalve 200 come together, and extends along the Tendon of Todaro of theheart. The second side of the triangle extends along the septal aspectof the annulus generally.

In the analysis, the tricuspid valve annulus 234 was identified byselecting two points on the annulus 234 in each image slice for imageplanes passing obliquely through the annulus, allowing for generation ofan interpolated curve through the data points. Additionally, curves weregenerated for the aortic valve commissures, the coronary sinus orifice206, and the TOK 224, which provided anatomic references or landmarkswith respect to the tricuspid valve annulus.

From the reconstructed anatomic references or landmarks, measurementswere made using the Mimics® software for each dataset, in order tocategorize the annulus shape. The measurements included the major axis230 and minor axis 232 dimensions of the valve annulus, the full annularperimeter, the partial annular perimeter 240 (clockwise perimeter withrespect to the annulus region bounded by the TOK 224), TOK height 226,and TOK length 228. In addition to the measured values, ratios werecomputed for the minor-to-major axis diameters and the partial-to-fullperimeters to assess the degree of annular circularity and thepercentage of the annular perimeter adjacent to the conductive tissuealong the septal aspect of the annulus. Tables 1 and 2 below providemeasurements and averages, standard deviations, maxima and minima forthe 5 CT datasets (CT1-CT5) and the 1 MRI dataset (MRI1).

TABLE 1 Measurements made in Mimics ® software for each of the sixdatasets. Case Full Perimeter (mm) Partial Perimeter (mm) Major (mm)Minor (mm) TOK H (mm) TOK L (mm) CT1 102.48 75.79 35.89 23.79 6.86 26.69CT2 104.77 85.52 32.68 31.57 6.06 19.25 CT3 120.54 103.01 42.60 35.236.19 17.53 CT4 127.96 110.89 41.80 39.33 12.90 17.07 CT5 135.97 111.4543.32 37.22 12.87 24.52 MRI1 147.26 126.02 49.19 42.99 14.29 21.24Average 123.16 102.11 40.91 35.02 9.86 21.05 STD 17.55 18.47 5.85 6.713.87 3.88 Max 147.26 126.02 49.19 42.99 14.29 26.69 Min 102.48 75.7932.68 23.79 6.06 17.07

TABLE 2 Ratios computed from minor/major axis dimensions andpartial/full perimeters. Case Minor:Major Axis Ratio Partial:FullPerimeter Ratio CT1 0.66 0.74 CT2 0.97 0.82 CT3 0.83 0.85 CT4 0.94 0.87CT5 0.86 0.82 MRI1 0.87 0.86 Average 0.85 0.83 STD 0.12 0.05 Max 0.970.87 Min 0.66 0.74

The curves generated for the tricuspid annulus, the aortic commissures,and coronary sinus orifice were outputted from the Mimics® software as3D points in Cartesian coordinate format, with the coordinate systemreferenced to MRI and CT scanners that were used. Using DPlot software(available from HydeSoft Computing, LLC, located in Vicksburg, Miss.,U.S.A.), a plane was computed for the tricuspid annulus points in 3Dspace using a least squares based algorithm. From the DPlot computedplane, residual offset (vertical offset) of each point from the planewas computed to assess the non-planarity of the annulus, with themaximum residual offset (positive direction), minimum residual offset(negative direction), and residual offset range computed for eachdataset. Table 3 provides the residual offset maxima, minima and rangesfor each dataset, and also provides the averages, standard deviations,maxima and minima.

TABLE 3 Residual offsets of tricuspid annulus data points from DPlotcomputed plane for each dataset. Residual Residual Reisudal Case OffsetMax (mm) Offset Min (mm) Offiset Range (mm) CT1 2.79 −4.00 6.78 CT2 6.79−6.19 12.98 CT3 4.90 −4.77 9.67 CT4 12.70 −9.95 22.65 CT5 4.27 −5.409.67 MRI1 4.58 −4.82 9.40 Average 6.00 −5.85 11.86 STD 3.52 2.14 5.64Max 12.70 −4.00 22.65 Min 2.79 −9.95 6.78

To assess the normal distance of each tricuspid annulus point from acomputed plane, the annulus curves for each dataset were loaded intoPro/ENGINEER (available from Parametric Technology Corporation, locatedin Needham, Mass., U.S.A.). The computed plane from D-Plot wasduplicated in Pro/ENGINEER using the coefficients of the plane equationcomputed from D-Plot. A Cartesian coordinate system was then defined inPro/ENGINEER, with the z-axis normal to the computed plane, and the xand y axes contained within the plane. The coordinate data of annuluspoints with respect to the newly defined coordinate system wereoutputted to Excel (available from Microsoft Corporation, located inRedmond, Wash., U.S.A.) to determine the normal distance (z-coordinate)of the points with respect to the Pro/ENGINEER computed plane, withmaximum, minimum, and range reported.

Finally, to locate maximum and minimum z-coordinate points in 3D space,a local cylindrical coordinate system (r,θ,z) was defined for eachdataset separately. FIG. 12 is a schematic representation showing howthe cylindrical coordinate system was defined with regard to theschematic representation of FIG. 11, in order to locate maximum andminimum z-coordinates along the tricuspid annulus. Center point 256 isthe centroid of the annulus coordinates in x and y. The line 250 thoughthe center point 256 (diameter of the circle) is an axis through thecenter point 256 and the peak 221 of the right coronary/non-coronaryaortic valve commissure. The line 252 is showing a radius (r) and theline 254 is showing the positive angular direction (θ) (clockwise) fromthe line 250 to the line 252. The plane of the drawing in FIG. 12 is theθ plane, with the z-axis extending normal to the drawing. The curves forthe aortic valve and tricuspid annulus were loaded into Pro/ENGINEER forthe analysis. The center point 256 for the coordinate system was definedby centering the x-y Cartesian coordinates of the annulus points suchthat the average of difference of individual x and y coordinates fromthe average x and y coordinates equals zero. Using the computed planeoriginally defined for the tricuspid annulus, axes were defined normalto the plane vertically through the center point of the annulus, andthrough the center point and the peak point of the aortic valvecommissure between the right coronary non-coronary cusps. First, themagnitude and angular position of the maximum and minimum z-coordinateswithin each dataset were located (Max 1 and Min 1, in Table 4). Second,the datasets were truncated or excluded from the center point of thetricuspid valve annulus toward the aortic valve side of the annulus, andthe magnitude and angular position of the second maximum and minimumz-coordinates were located (Max 2 and Min 2, in Table 4).

TABLE 4 1^(st) and 2^(nd) maximum and minimum z-coordinates for eachdataset along with angular position in cylindrical coordinate system.Max1 Max 2 Min1 Min2 Case z (mm) θ Position (deg) z (mm) θ Position(deg) z (mm) θ Position (deg) z (mm) θ Position (deg) CT1 1.4 −109.5 1.2112.8 −2.0 182.9 −0.9 329.9 CT2 1.9 7.2 0.9 124.5 −1.8 56.6 −1.6 254.7CT3 2.1 −78.1 1.4 213.0 −2.1 21.8 −1.4 86.8 CT4 2.6 10.2 1.0 158.6 −2.0247.0 −1.0 55.2 CT5 1.6 −26.7 1.8 185.4 −2.2 267.2 −1.6 110.0 MRI1 3.9−82.7 1.6 129.9 −3.7 255.1 −3.0 57.1 Average 2.3 −46.6 1.3 154.0 −2.3171.8 −1.6 149.0 STD 0.9 50.5 0.3 39.1 0.7 107.3 0.8 115.3 Max 3.9 10.21.8 213.0 −1.8 267.2 −0.9 329.9 Min 1.4 −109.5 0.9 112.8 −3.7 21.8 −3.055.2 Range 2.5 119.7 0.8 100.2 1.9 245.4 2.1 274.6

From analysis of the data, general trends were observed. The ratio ofthe minor-to-major axis diameters showed that the annuli werenon-circular for the cases analyzed, with a maximum ratio of 0.97, aminimum of 0.66, and an average value of 0.85. The partial:fullperimeter ratios showed a maximum of 0.87, and minimum of 0.74, and anaverage of 0.83, indicating that the conductive tissue region makes upapproximately 17% of the annular perimeter. The residual offset dataindicated clearly that the annulus is non-planar, with the averagemaximum and minimum approximately 6 mm and the range approximately 12mm. The maximum and minimum z-coordinate data indicated average normaloffsets of Max 1 and Min 1 data points from the computed plane ofapproximately 2.3 mm, with Max 2 and Min 2 offset by 1.3 and 1.6 mm,respectively. By locating the positions of the maximum and minimumz-coordinates, the results showed the largest positive z-coordinatealong the annulus was generally located near the aortic valve,counterclockwise from the right coronary/non-coronary commissure. Theresults also showed a general rise of the annular points in the positivez direction (direction superior to the computed plane) from the septaland anterior aspects of annulus toward the aortic valve for somedatasets (particularly MRI1). This result suggests a saddle-shapedannulus.

Based on the analysis of the six datasets, the tricuspid valve annuluscan be defined as a non-circular and non-planar shaped tissue structure,with a general relationship of minimum points along the septal andanterior aspects of the annulus and a rise up to a maximum height nearthe right coronary/non-coronary commissure of the aortic valve. Thesedata suggest a distinct relationship between the tricuspid valve and theaortic valve, where the shape of the tricuspid valve near itsinteraction with the aortic valve may facilitate appropriate aorticvalve function. Therefore, surgical repair procedures of the tricuspidvalve should attempt to maintain this distinct relationship to bothrestore tricuspid valve function and maintain proper aortic valvefunction. In addition to this relationship, a consistent relationshipwas observed across the datasets for the TOK, indicating that theconductive tissue region of the heart near the tricuspid annulus makesup approximately 17% of the tricuspid annulus perimeter. This provides areference point for appropriate termination of surgical repair of thetricuspid annulus along the septal annulus to avoid damage to theconductive tissue. General ranges for the preferred shape/design of atricuspid valve annuloplasty device are defined in Table 5 below (basedon averages of above data, plus or minus one standard deviation).

TABLE 5 General ranges for shape/design of a tricuspid valveannuloplasty device. Range 2D (Short Axis) Shape - Minor:Major Ratio0.75-0.96 Percentage of Device Perimeter to Exclude Along 12-22% SeptalAspect of Annulus to Avoid Conductive Tissue Residual (Vertical) OffsetRange of Maximum and 6.2-17.5 mm Minimum Points from Computed PlaneThrough Device Normal Offset of Maximum and Minimum Points −3 to +3 mmfrom Computed Plane Through Device Angular Position of Maximum NormalOffset With −100 to 0 degrees Respect to Axis Through Center Point ofDevice and Point on Device Closest to Right Coronary/Non- coronaryCommissure

It is to be understood that while particular embodiments of the presentinventive annuloplasty device have been illustrated for use in typicalvalve repair procedures, various modifications to shape, and arrangementof parts can he made as may be desirable for varying applications as mayrelate to valve sizes, disease states, or later developed techniques.

The present invention has now been described with reference to severalembodiments thereof. The entire disclosure of any article, patent orpatent application identified herein is hereby incorporated byreference. The foregoing detailed description has been given for clarityof understanding only. No unnecessary limitations are to be understoodtherefrom. It will be apparent to those skilled in the art that manychanges can be made in the embodiments described without departing fromthe scope of the invention.

The invention claimed is:
 1. An annuloplasty device for implantationadjacent an annulus of a tricuspid valve, the annulus comprisinganterior, posterior and septal aspects adjacent anterior, posterior andseptal leaflets, respectively, of the tricuspid valve, the devicecomprising: a ring body comprising: an anterior portion, a posteriorportion and a septal portion shaped to conform to, and for implantationadjacent, the anterior, posterior and septal aspects of the annulus,respectively; and first and second end portions that are more flexiblethan a remainder of the ring body to provide a gradual transition fromthe remainder of the ring body to tissue of the tricuspid valve annulus;wherein the ring body is curvilinear, with substantially no flatportions along at least the anterior portion in any of three dimensions,and forming a shape.
 2. The annuloplasty device of claim 1 wherein thering body is configured such that when the device is implanted, thefirst end portion will be located near a junction of the septal andanterior aspects of the annulus and the second end portion will belocated near the septal aspect of the annulus.
 3. The annuloplastydevice of claim 1, wherein the ring body further comprises: a sheath;and, a stiffening element disposed within the sheath.
 4. Theannuloplasty device of claim 1, wherein first and second end portions ofthe ring body comprise a flexible material.
 5. The annuloplasty deviceof claim 3, wherein the stiffening element comprises a diameter that isreduced towards first and second ends of the stiffening element suchthat the stiffening element is more flexible towards the first andsecond ends.
 6. The annuloplasty device of claim 1, wherein the anteriorportion comprises a curve extending in a superior direction, theposterior portion comprises a curve extending in the superior direction,the anterior portion curve extends farther in the superior directionthan the posterior portion curve.
 7. The annuloplasty device of claim 1,wherein the ring body mimics the shape of a native tricuspid valveannulus.
 8. The annuloplasty device of claim 1, wherein the curvilinearshape includes varying slope between four slope minima.
 9. Theannuloplasty device of claim 1, wherein the ring body follows a pathfrom first end portion to second end portion that contains at least twomaximum and two minimum positions along the path.
 10. The annuloplastydevice of claim 1, wherein upon implantation, the end portions of thering body avoid the AV node of the heart.
 11. The annuloplasty device ofclaim 1, wherein upon implantation, the end portions of the ring bodyavoid the Triangle of Koch of the heart.
 12. The annuloplasty device ofclaim 1, wherein relative to an upright orientation of the device inwhich the first end is spatially above the second end in a verticaldimension, an upward direction is spatially defined from the second endtoward the first end, and an opposite, downward direction is definedfrom the first end toward the second end, and further wherein extensionof the ring body from the first end includes a curve in the downwarddirection from a first maxima to a first minima, a curve in the upwarddirection from the first minima to a second maxima, a curve in thedownward direction from the second maxima to a second minima, and aprojection in the upward direction from the second minima to the secondend.
 13. An annuloplasty device for implantation adjacent an annulus ofa tricuspid valve, the annulus comprising anterior, posterior and septalaspects adjacent anterior, posterior and septal leaflets, respectively,of the tricuspid valve, the device comprising: a ring body comprising:an anterior portion, a posterior portion and a septal portion shaped toconform to, and for implantation adjacent, the anterior, posterior andseptal aspects of the annulus, respectively; and first and second endportions; wherein the ring body is curvilinear, with substantially noflat portions along at least the anterior portion in any of threedimensions, forming a shape, and the ends are configured such that whenthe device is implanted, the first end will be located near a junctionof the septal and anterior aspects of the annulus and the second endwill be located near the septal aspect of the annulus, and the anteriorportion comprises a curve extending in a superior direction thatincludes a peak and the peak will be located within about 20 degreesfrom the junction of the septal aspect and the anterior aspect of theannulus and located adjacent the anterior aspect of the annulus whenimplanted.
 14. The annuloplasty device of claim 13, wherein the peak ofthe anterior portion will be located about 10 to about 20 degrees fromthe junction of the septal and the anterior aspects of the annulus andlocated adjacent the anterior aspect of the annulus when implanted. 15.The annuloplasty device of claim 14, wherein the posterior portioncomprises a curve extending in the superior direction, the anteriorportion curve extending farther in the superior direction than theposterior portion curve.
 16. The annuloplasty device of claim 13,wherein the peak of the anterior portion will be located adjacent thejunction of the septal aspect and the anterior aspect of the annuluswhen implanted.
 17. The annuloplasty device of claim 13, wherein theposterior portion comprises a curve extending in the superior direction,the anterior portion curve extending farther in the superior directionthan the posterior portion curve.